Lead forming method

ABSTRACT

A method of attaching the leads of coils wound onto a slotted armature with the leads wrapped at least partially around the shaft of the armature and then connected to selected commutator hooks circumferentially spaced from the slots in which the coils are laid, which method is characterized by the fact that a pair of concentric sleeves shield the commutator to prevent engagement of the wire with the hooks during winding of the coils; and upon completion of a pair of simultaneously wound coils, rotation of the concentric sleeves both in unison and relative to one another, first in one direction and then the other, exposes the selected hooks and wraps the wire lead about them.

United States Patent Dammar Reissued Oct. 28, 1975 [5 LEAD FORMINGMETHOD 3,212,170 10/1965 Marshall 29/598 3,309,548 3/1967 Gou h et al.310/234 [75] Inventor: E Dammar Mmneapolls 3,395,448 8/1968 Moo re29/596 3,395,449 8/1968 Moore 29/596 [73]. Assigneez Possis Corporation,Minneapolis, 3,448,311 6/1969 Mommsen et ai. 310/234 Minn. FOREIGNPATENTS OR APPLICATIONS [22] Filed 1972 121,253 4/1966 Netherlands29/597 21 App]. No.: 280,037

Related U.S. Patent Documents Primary Examiner 'carl Hall Reissue of:

[64] Patent No.: 3,636,621 [57] ABSTRACT Issued: Jan. 25, 1972 PP N05,832 A method of attaching the leads of coils wound onto a Filed: Aug.26, 1968 slotted armature with the leads wrapped at least par- 21Division of Ser. No. 565,291, July 14, 1966. tially around the shaft ofthe armature and then con- 1 1 nected to selected commutator hookscircumferentially spaced from the slots in which the coils are laid, I 1Cl 29/205 which method is characterized by the fact that a pair 2 21: 22/ of concentric sleeves shield the commutator to pre- 310/234 ventengagement of the wire with the hooks during [51] Int. Cl.2 02K 15/00winding of the oils; and upon completion of a pair of Field 05 Search29/596, 598, 205 R, simultaneously wound coils, rotation of theconcentric 29/205 CM; 140/92.1;242/7.03,7.05 B; sleeves both in unisonand relative to one another, 310/234 first in one direction and then theother, exposes the selected hooks and wraps the wire lead about them.[56] References CIted UNITED STATES PATENTS 3,169,301 2/1965 Fletchen etal 29/205 )4 4 Claims 31 Drawing Figures 3,191,269 6/1965 Moore 29/598Reissued Oct. 28, 1975 Sheet 1 of7 Re. 28,582

I N VEN TOR. RA YMON l1. DA MMAR B Y JW,M W w A7- TORNE Kr Reissued Oct.28, 1975 Sheet 2 of7 Re. 28,582

m d QN [N VENTOR. AA YMON H. DA MMAR A7- TORNEYJ' Reissued 0m. 28, 1975Sheet 4 of7 Re. 28,582

1N VENTOR. IFAYMoN/iDAA/IMAR Reissued Oct. 28, 1975 Sheet 5 of7 Re.28,582

INVENTUR. RA YMo/v ILDA MMAR .WN E

Reissued Oct. 28, 1975 Sheet 6 of7 Re. 28,582

QM r k INVENTOR. AA YMON H. DAMMAI? ,filwddocg ATrok/VEKY Reissued Oct.28, 1975 Sheet 7 of7 Re. 28,582

QM k M E 1 N VEN TOR. AA YMON h. DA MMAI? BIG $946M Ar TORNEYJ LEADFORMING METHOD Matter enclosed in heavy brackets appears in the originalpatent but forms no part of this reissue specification; matter printedin italics indicates the additions made by reissue.

This application is a division of the copending application Ser. No.565,291, filedJuly 14, 1966, now US. Pat. No. 3,474,515. I

This invention relates to a method of attaching the leads of coils woundonto a slotted armature core, to the hooks or tangs of the commutator ofthe armature, and has as its purpose to expeditiously produce armaturesthat are free'from objectionable crossover loops and undesirablebridging.

Briefly, the method of this invention contemplates shielding thecommutator of the armature and, more especially, its lead-receivinghooks or tangs, in the mouth of a pair of concentric relativelyrotatable sleeves during the winding of the coils to prevent engagementof the wire with the hooks or tangs, and then -at the completion of eachcoil and with the wire held against the outer sleeve-carrying the wirearound the armature shaft by rotation of the outer sleeve to a pointjust beyond a selected commutator hook. At this point, the selected hookis exposed by relative rotation between the sleeves and the wire dropsbehind the selected hook. Now, by rotation of the sleeves in unison, butin the reverse direction, the wire is carried around the hook, whereuponrelative rotation of the sleeves frees the wire from the concentricsleeves so that winding of the next coil can commence.

It is a feature of this invention that, during the attachment of thewire lead to a commutator hook, the armature is not rotated. The onlyrotation imparted to the armature is that required to index it for thewinding of successive coils.

With these observations and objectives in mind, the manner in which theinvention achieves its purpose will be appreciated from the followingdescription and the accompanying drawings, which exemplify theinvention, it being understood that changes may be made in the precisemethod of practicing the invention and in the specific apparatusdisclosed herein without departing from the essentials of the inventionset forth in the appended claims.

The accompanying drawings illustrate one complete example of thephysical embodimentof the invention constructed according to the bestmode so far devised for the practical application of the principlesthereof, and in which:

FIG. 1 is a plan view of an apparatus that can be employed to practicethe method of this invention, illustrating an armature in position andbeing wound;

FIG. 2 is a side view of the apparatus shown in FIG. 1, partly insection;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2; 1

FIG. 4 is a sectional view taken along the line 44 of FIG. 1;

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 1;

FIG. 6 is an enlarged sectional view taken along the line 66 of FIG. 2;

FIG. 7 is an enlarged viewsimilar to FIG. 5 showing a detail of thedrive control of the apparatus;

FIG. 8-is an enlarged sectional view taken along the line 8-8 of FIG. 1;

FIG. 9 is a fragmentary plan view of the structure shown in FIG. 8;

FIG. 10 is a sectional view taken along the line 10-10 of FIG. 9;

" FIGS. 11 and 12 are sectional views similar to F IG. 10 to illustratehow rotation of the outer sleeve carries the wire lead around the shaft;

FIG. 13 is a top view of the structure shown in FIG. 12 taken along line13l3;

FIG. 14 is a sectional view similar to FIG. 10 showing the wire leadcarried to the point at which it drops behind the selected commutatorhook;

FIG. 15 is a fragmentary plan view taken along line 15-15 of FIG. 14;

FIG. 16 is an enlarged sectional view taken along the line 1616 of FIG.14;

FIG. 17 is a sectional view similar to FIG. 10 showing how reverserotation of the sleeves wraps the lead wire about the selectedcommutator hook;

FIG. 18 is a sectional view similar to FIG. 10 showing how duringrelative rotation of the sleeves in the reverse direction the lead wireis disnegaged from the inner member;

FIG. 19 is a plan view of the structure shown in FIG. 18;

FIG. 20 is a sectional view similar to FIG. 10 showing the situation asit obtains preparatory to the indexing of the rotor for winding the nextcoil;

FIG. 21 is a plan view of the structure shown in FIG. 20 with partsbroken away to show the lead wrapped around the hook;

FIG. 22 is a sectional view similar to FIG. 20 showing the rotor indexedto the next coil receiving position; and

FIGS. 23 to 31 are diagrammatic views partly sectioned showing thesequential relationships between the driving control structure of theapparatus and the movable lead-carrying structure with respect to thelead receiving hook on the commutator.

Referring to the drawings there is shown in FIG. 1, a rotor for anelectrical machine indicated generally at 35 positioned in workingrelation with a lead-attaching apparatus indicated generally at 44.Rotor 35 has a soft iron armature core 36 formed with a plurality ofcircumferentially spaced longitudinal slots for receiving coils of wire37 forming electrically effective coil loops.

The coils of wire are wound or placed on armature core 36 by a windingmachine (not shown) having movable fliers 38 for directing the wireleads 39 into pairs of slots in the armature core. Axially spaced fromcore 36 is a commutator 41 mounted on a shaft 42 carrying armature core36. Commutator 41 has a plurality of circumferentially spaced conductingsegments forming an outer cylindrical surface. Each segment of the core36 has a hook or tang 43 turned upwardly and axially away from the coreto receive and hold leads 39 extended from the slots.

The lead-attaching apparatus 44 operates in conjunction with the windingmachine to carry the ending leads which extend from the slots around theshaft and onto commutator hooks that are circumferentially spaced fromthe slots from which the leads emanate, in a manner which eliminatescrossover loops and bridging of successive leads. As shown in FIG. 2,the apparatus 44 has a flat frame or base plate 46 carrying a box shapedhousing 47. Frame 46 has a plurality of elongated openings adapted toreceive bolts used to secure the frame to a machine support 45 or thelike. Housing 47 has a longitudinal bore accommodating an elongatedouter tubular shaft 48. Ball bearing assemblies 49 and 51 rotatablymount shaft 48 in housing 47. Concentrically positioned within tubularshaft 48 is an inner shaft 52. Sleeve bearings 53 and 54 located in theopposite end portions of shaft 48 rotatably mount shaft 52 withintubular shaft 48.

Mounted on the forward end of shafts 48 and 52 is a commutator shieldingand lead moving and guiding unit 55 which is operable to move and guideeach end ing wire lead which extends from the coil just wound, aboutrotor shaft 42 and around a selected commutator hook while at the sametime shielding the entire commutator except the selected hook to therebyprevent other or previously attached leads from leaving their hooks. Asshown in FIG. 16, unit 55 comprises an outer sleeve or cup member 56telescoped over and secured to the end of tubular shaft 48 by screws 57.Projected radially from the forward portion of sleeve 56 are twodiametrically opposite lugs or fingers 58 and 59. These fingers areidentical in construction as shown in FIGS. 9 and 10, and they havefront or leading faces which lie in a common plane that contains theaxis of the shafts 48 and 52. The opposite trailing and outward sidefaces of the lugs are each inclined and converge to flat heads havingrearward projections 61. Axial recesses 62 are located in the bottomportions of the trailing faces. Located adjacent to the leading face offinger 58 is a triangular-shaped groove 63 having an inclined plowingedge 64. A similar triangular groove 63A is located ad.- jacent to theleading face of finger 59 to provide a plowing edge 64A.

Concentrically disposed within sleeve 56 is an inner sleeve whichprovides a thimble or inner cup member indicated generally at 65, thecylindrical interior of which forms a chamber 66 for receiving andshielding the entire commutator 41. Cup member 65 has a base 67 and anoutwardly projected cylindrical flange 68.

Base 67 is drivably connected with the inner shaft 52 by a radiallydisposed pin 69 which has its inner end portion fixed in a hole in shaft52 and its outer end por tion received in an arcuate slot 71 in base 67.The arcuate length of the slot 71 provides the connection between theinner shaft 52 and the cup member 65 with about 20 of lost motion.

A frictional driving connection between the cup member 65 and the outersleeve 56 is provided by a plurality of circumferentially spaced shoes72 located in radial recesses 73 in base 67. Springs 74 positioned inrecesses 73 bias the shoes radially outwardly into frictional engagementwith the inner surface of outer sleeve 56.

As shown in FIG. 16, the forward end of inner shaft 52 has an axial bore76 to receive the shaft 42 of an armature to be wound. Bore 76 axiallyaligns the armature core with the lead moving and guiding unit to insurethe location of commutator 41 within the chamber 66.

The cylindrical flange 68 of the shielding cup or thimble has axialslots 77 and 78 which open to the outer end of member 65 and arenormally covered by the outer sleeve 56. When uncovered by relativerotation of the inner and outer sleeves the slots 77 and 78 are locatedimmediately adjacent the leading ends of the plowing edges 64 and 64Arespectively, and when so uncovered, the slots 77 and 78 receive thewire leads and allow them to be engaged over and around the commutatorhooks.

As shown in FIG. 4, the concentric shafts 48 and 52 are rotated byreciprocation of a rack 79 which meshes with a pinion gear 81 fixed withrespect to the outer shaft 48. The rack extends transversely through anopening in housing 47 and has its opposite ends secured to pistons 82and 83 operative in cylinders 84 and 86 respectively. The inner ends ofthe cylinders are secured to housing 47 and close the opening 80. Caps87 and 88 secured to the outer ends of the cylinders 84 and 86 arecoupled to lines 89 and 91 used to supply pressure fluid, preferablyair, to selectively drive the pistons toward housing 47. The top of rack79 rides on a bearing plate 92 transversely positioned in housing 47 andsecured to the top of housing 47 by bolts 93. As shown in FIG. 2, plate92 has an elongated rectangular guideway for racks 79 and maintains theteeth of the rack in meshing engagement with the teeth of pinion gear81.

As shown in FIGS. 2 and 3, a clamp unit comprising a sleeve portion 94and a clamp portion 96 located in housing 47 is attached to outer shaft48 by bolts 97. Sleeve portion 94 has a radial flange surrounding outershaft 48 and accommodating bolts 98 securing pinion gear 81 to sleeveportion 94 so that on rotation of pinion gear 81 the outer shaft isrotated. Outer shaft 48 rotates approximately as determined by a pair oflimit switches 99 and 101 mounted on opposite sides of housing 47 asshown in FIG. 1. These switches have forwardly projected actuators 102and 103 which control suitable valves (not shown) for directing thepressure fluid to cylinders 84 and 86 respectively. Actuators 102 and103 are controlled by the angular positions of a pair of collars 104 and106 adjustably mounted on outer shaft 48. The collars have radiallydirected arms 107 and 108 respectively which engage actuators 102 and103 to determine the clockwise and counterclockwise stop positions ofouter shaft 48.

Rotational movement of outer shaft 48 with respect to inner shaft 52 isregulated by a drive control indicated generally by 109 in FIGS. 1,2,5and 7. Drive control 109 comprises a radial arm 1 11 having a bifurcatedinner end clamped about the end of inner shaft 52 with a bolt 112. Arm111 is engaged by a rearwardly projected pin 113 secured to a collar114. A fastening means 115, as a setscrew, adjustably mounted collar 114on outer shaft 48 to provide a positive driveconnection between collar114 and outer shaft 48. A coil spring 116 concentrically disposed aboutthe rear end of inner shaft 52 provides a resilient driving connectionbetween pin 113 and arm 111. Spring 116 has one end hooked over pin 1 13and its opposite end hooked about the inner edge of arm 1 11 so as toresiliently urge arm 111 into engagement with pin 1 13.

On rotation of outer shaft 48 in response to the application of fluidpressure to cylinder 84, the outer shaft 48 and inner shaft 52 rotatetogether by reason of the friction drive established by shoes 72. Therotating inner shaft 52 carries arm 1 11 toward and into engagement withan adjustable stop 117. As shown in FIG. 7, when arm 111 engages thestop 117 inner shaft 52 is prevented from further rotation, but theouter shaft 48 continues to rotate the inner cup member 65 an amountequal to the lost motion of pin 69 in angular slot 71. During thismovement pin 113 moves away from arm 111 against the biasing force ofspring 116.

On reversing the direction of the movement of rack 79 by applying fluidpressure to cylinder 86 the outer sleeve 48 rotates in a reversedirection moving pin 113 back into engagement with the arm 111. Spring116 holds arm 111 into engagement with stop 117. Inner cup member 65rotates with sleeve 56 until the lost motion provided by the slot 71 istaken up. At this time sleeve 56 rotates relative to cup member 65overriding the friction drive of shoes 72 until pin 1 13 engages arm111. Arm 11 1 is then carried back to its initial position by pin 113allowing cup member 65 to be moved with sleeve 56 back to their startingpositions.

In use, rotor 35 is held by the winding machine in an indexed positionwith its shaft 42 in bore 76 of the lead moving, guiding and shieldingunit 55. The entire commutator 41 is positioned in cylindrical chamber66 with the ends of its hooks 43 close to flange 68 to prevent appliedleads from coming off the hooks and shielding the hooks from the wire asit is wound on core 36. Movable fliers 38 of the winding machine windthe wire leads 39 in separate pairs of core slots around core 36 to formthe coils 37. As shown in FIG. 1, ending leads 39 from coils 37 extendfrom the core 36 adjacent to the top and bottom portions of outer sleeve56. The following description is directed to the movement of the leftlead 39 located under the sleeve 56 and engageable with finger 59. Theopposite or right lead is moved and hooked in a similar manner andengages finger 58.

Referring to FIG. 8, 9 and 10, core 36 is in an indexed position withthe coils 37 wound on the core in substantially vertical planes bymovable fliers 38. Bottom lead 39 extends from coil 37 rearwardly aroundthe flier pulley adjacent the bottom of sleeve 56 forwardly of finger59. When coil 37 is completed the winding machine sends a signal whichactuates a valve (not shown) to supply fluid under pressure to cylinder84 driving piston 82 to the left as shown in FIG. 4. The consequentmovement of rack 79 positively rotates outer shaft 48 and by virtue ofthe frictional driving connection, the inner shaft 52 is likewiseturned. Since the sleeve 56 is fixed to the outer shaft, it too ispositively rotated, and in so doing moves finger 59 into engagement withending lead 39 carrying the lead in an upward direction as shown byarrow 118 in FIG. 11. As the sleeve 56 continues to rotate lead 39 fallsinto groove 63A in the outer edge of sleeve 56 adjacent the forward sideof finger 59. As shown in FIGS. 12 and 13, lead 39 is movedcircumferentially around the shaft 42 and retained in groove 63A by thetension on the lead from the winding machine.

FIGS. 23, 24 and 25 show outer sleeve 56 rotated in the clockwisedirection with finger 59 moved upwardly along with the arm 111 of thedrive control 109. FIG. 25 compares with FIG. 12. In this position arm111 engages stop 117 thereby preventing further rotation of inner shaft52. The inner cup member 65 continues to rotate with outer sleeve 56 byreason of the friction drive established by the shoes 72 as shown inFIG. 6 and the lost motion of slot 71 and pin 69. Cup member 65continues to rotate with outer sleeve 56 until pin 69 engages theopposite wall of slot 71 as shown in FIGS. 7 and 26. Continued rotationof outer shaft 48 then moves outer sleeve 56 relative to cup member 65until slot 78 is in alignment with groove 63A as shown in FIGS. 15, 16and 27. In this position finger 59 has carried ending lead 39approximately around shaft 42. The tension on lead 39 maintained by thewinding machine moves the lead forwardly into slot 78. The depth of slot78 is sufficient to allow the lead to move to the far side of hook 43 ofcommutator 41. As shown in FIG. 16, lead 39 is in slot 78 and ispositioned below and forwardly of the end of the hook.

At this point arm 108 engages actuator 103 of switch 101 and therebyterminates the flow of pressure fluid into cylinder 84 and actuates avalve (not shown) by which the pressure fluid is directed to cylinder 86thereby reversing the direction of rotation of outer shaft 48. As shownin FIGS. 27 and 28, arm 111 is held in engagement with stop 117 duringthe initial reverse movement of the shaft 48 by spring 1 16interconnecting arm 1 11 with pin 113. In FIG. 27, slot 78 is adjacentthe forward side of hook 43. On initial reverse rotation of outer sleeve56 cup member 65 moves with sleeve 56 with slot 78 aligned with groove63A carrying lead 39 under hook 43 as shown in FIG. 17. Slot 78 andgroove 63A move together because of the lost motion of pin 69 in angularslot 71. Pin 69 holds cup member 65 from further reverse relativerotation with respect to inner shaft 52 thereby fixing the angularlocation of slot 78.

The outer sleeve 56 continues to rotate because of its positive driveconnection with outer shaft 48. Spring 116 holds arm 111 in engagementwith stop 117 thereby preventing rotation of inner cup member 65. Sleeve56 rotates in a reverse direction relative to cup member 65 since theforce of spring 1 16 is greater than the friction drive of shoes 72 onsleeve 56. This relative rotation between the outer sleeve 56 and cupmember 65 moves the inclined plowing edge or surface 64A across slot 78forcing the wire lead 39 out of the slot and onto the end of sleeve 56thereby moving the wire lead in a backward direction adjacent the rearside of hook 43. This completes the placement of the lead about hook 43and places the hook in a shielding position within chamber 66. FIGS. 18and 19 show how the plowing edge or surface 64A moves the wire lead 39around hook 43 out of slot 78.

As shown in FIG. 29, pin 113 is moved into engagement with arm 111whereby the outer shaft 48 drives inner cup member 65 and sleeve 56together back to their initial positions. As the sleeve 56 continues torotate back to its initial position the opposite finger 58 engages lead39 as shown in FIGS. 20 and 21. The lead is retained on the finger as itfalls into recess 62 on the trailing side of the lug. As shown in FIG.30, pin 113 is in contact with arm 111 establishing a positive driveconnection between'the outer shaft and the inner shaft. Cup member 65 isin frictional drive relationship with outer sleeve 56 since pin 69engages the trailing side of slot 71. This location of pin 69 in slot 71is maintained during the indexing of the rotor to the next position forreceiving additional coils of wires as shown in FIG. 31. FIG. 22 showsthe position of the trailing portion of the last wound coil lead locatedapproximately 180 around shaft 42 and around commutator hook 43. Thecommutator has been indexed to the next position for receivingadditional coils in adjacent pairs of slots. During the indexing of therotor the fingers 58 and 59 are not rotated as-therotor shaft 42 is freeto turn in bore 76.

Each succeeding terminating lead for each of the coils wound on the coreis moved circumferentially around a portion of the shaft located betweenthe core and the commutator and around the commutator hook y from thefar side in the manner described untilthe desired number of coils have,been wound on the core.

During the winding of any coil all of the leads already connected tocommutator hooks are sheil'ded by the cup-shaped member 65. Thisprevents the leads from becoming unhooked from the commutator hooks and1 unit. With the commutator shielded one or more coils I of wire areplaced in separate circumferentially spaced slots of the slotted core.When the coils are completed the terminating leads which extend from theslots are located adjacent to the shielded commutator in engage mentwith the lead moving and guiding unit. The terminating lead of each coilis carried circumferentially around the shaft carrying the core byrotation of the lead moving and guiding unit. This places the lead extended from the core close to the shaft and eliminates bridging ofsuccessively applied leads. The leads are then placed about selectedhooks with all hooks except the selected hooks remaining shielded. Thisis done by moving the leads in axial directions away from the coreadjacent the farm forward side of the selected commutator hooks; Theleads are then carried a short distance back in a circumferentialdirection under the selected hooks, and then moved in axial directionstoward the core adjacent the rear side of the hooks thereby placing theleads around the selected commutator hooks. The selected hooks are onlyunshielded during the time the leads are carried circumferentially backto locate the leads under the hooks.

Those skilled in the art will appreciate that the invention can beembodied in forms other than as herein disclosed for purposes ofillustration.

The invention is defined by the following claims:

1. A method of winding an armature having a core with circumferentiallyspaced coil-receiving slots, a

commutator having segments with lead-receiving hooks to which leads fromcoils that are wound into pairs of the slots are attached, and a shafton which the core and the commutator are mounted in axially spacedrelation, said method comprising the steps of:

A. shielding the entire commutator by inserting the same into an openend portion of the inner one of a pair of concentric sleeve members thatare rotatable together and with respect to one another;

B. winding a coil in a pair of circumferentially spaced slots of thearmature core while the commutator is thus shielded;

C. upon completion of the coil; holding the ending lead thereof tautand" alongside the portion of the armature shaft between the core andthe commutator and adjacent to the shielded commutator;

D lby rotation of the outer sleeve member in one direction, moving saidlead circumferentiallyabout the axis of the armature into tangentialengagement with said portion ofthe armature shaft and into juxtaposition to a selected' commutator hook that is Reqzassgcircumferentially spaced from the coil slot from which the leademanates;

E. by relative rotation between the sleeve members, exposing only theselected hook and placing the lead in position to be engaged with saidhook;

F. by rotation together and relative to one another of both sleevemembers in the opposite direction,

completing engagement of the lead with the hook, reshielding said hook,moving the lead which now extends from said hook [circumferentiallyabout the axis of the armature into position to enter directly into thefirst of the next pair of coil-receiving slots;

G. with all of the hooks of the commutator again shielded and with thearmature indexed to bring said next pair of slots into winding position,placing the lead directly into the first of said pair of slots to beginthe next coil and completing the winding of said next coil; and

H. repeating the aforesaid steps until all coilreceiving slots have hadcoils wound into them.

2. The method of claim 1, wherein the lead is moved circumferentiallyaround the axis of the armature between and 270 from the coil slot fromwhich it emanates in being brought into juxtaposition to the selectedcommutator hook,

3. The method of claim 1, wherein during the first movement of the leadcircumferentially about the axis of the armature, the lead is placedadjacent to one side of the selected hook,

and wherein during the second movement of the lead [circumferentiallyabout the axis of the armature] the lead is carried under and placed atthe opposite side of the selected hook.

said selected hook being unshielded only during the time the lead iscarried under said hook.

4. The method of claim 1, wherein a pair of coils are simultaneouslywound in two pairs of coil slots,

and wherein the ending leads from the two coils are simultaneouslyengaged with selected commutator hooks, while all of the other hooksremain shielded.

[5. In the winding of an armature having a core circumferentially spacedslots, into pairs of which coils are successively wound, a commutatorhaving segments with books onto which leads from the coils are attached,and a shaft on which the core and the commutator are mounted in axiallyspaced relation, the improvement by which crossover loops andundesirable bridging of leads of are eliminated and which improvement isachieved by:

A. shielding the commutator hooks;

B. with the commutator hooks shielded, winding a coil of wire into apair of circumferentially spaced core slots;

C. upon completion of the coil, holding the ending lead of the coil tautand alongside the portion of the armature shaft between the core andcommutator;

D. effecting relative motion between the tautly held lead and thearmature about the axis of the armature to bring the lead intotangential engagement with said portion of the shaft;

E. with the tautly held lead bearing tangentially against sa-id portionof the shaft, rendering accessible'a selected commutator hook that iscircumferentially spaced from the coil slot from which the lead emanatesand effecting relative motion between the lead and the armature toproduce engagement of the lead with said selected hook,

F. reshielding the selected commutator hook;

G. again effecting relative motion between the tautly held lead and thearmature about the axis of the armature to thereby engage the leadaround the selected commutator hook;

H. with the armature indexed to dispose the pair of slots into which thenext coil is to be wound in winding position, carrying the lead directlyinto the first of said pair of slots with said stretch of the lead thatextends from the engaged commutator hook bearing tangentially againstsaid portion of the armature shaft, and resuming the winding operation;and

l. repeating the aforesaid steps until all of the core slots have coilswound therein.

[6. In the winding of an armature, the improvement set forth in claim 5,wherein said relative motion between the tautly held lead and thearmature is PK duced by impartingg motion to the tautly held lea whilethe armature remains stationary.

7. The method of claim 6, wherein during said fir: relative motion, thetautly held lead is moved in one d. rection around the axis of thearmature beyond the se lected commutator hook so that the lead engagesbe hind the hook, and

wherein said second relative motion is in the revers direction to carrythe lead around the hook.]

I 8. The method of the claim 6, wherein the shield ing of the commutatorhooks is done by placing the en tire commutator in a cup-shaped chamber,and

wherein the relative motion between the tautly helc lead and thearmature is effected by establishing 2 connection between the lead andthe side of saic chamber and rotating the chamber around the commutator.

1. A method of winding an armature having a core with circumferentiallyspaced coil-Receiving slots, a commutator having segments withlead-receiving hooks to which leads from coils that are wound into pairsof the slots are attached, and a shaft on which the core and thecommutator are mounted in axially spaced relation, said methodcomprising the steps of: A. shielding the entire commutator by insertingthe same into an open end portion of the inner one of a pair ofconcentric sleeve members that are rotatable together and with respectto one another; B. winding a coil in a pair of circumferentially spacedslots of the armature core while the commutator is thus shielded; C.upon completion of the coil; holding the ending lead thereof taut andalongside the portion of the armature shaft between the core and thecommutator and adjacent to the shielded commutator; D. by rotation ofthe outer sleeve member in one direction, moving said leadcircumferentially about the axis of the armature into tangentialengagement with said portion of the armature shaft and intojuxtaposition to a selected commutator hook that is circumferentiallyspaced from the coil slot from which the lead emanates; E. by relativerotation between the sleeve members, exposing only the selected hook andplacing the lead in position to be engaged with said hook; F. byrotation together and relative to one another of both sleeve members inthe opposite direction, completing engagement of the lead with the hook,reshielding said hook, moving the lead which now extends from said hook(circumferentially about the axis of the armature) into position toenter directly into the first of the next pair of coil-receiving slots;G. with all of the hooks of the commutator again shielded and with thearmature indexed to bring said next pair of slots into winding position,placing the lead directly into the first of said pair of slots to beginthe next coil and completing the winding of said next coil; and H.repeating the aforesaid steps until all coil-receiving slots have hadcoils wound into them.
 2. The method of claim 1, wherein the lead ismoved circumferentially around the axis of the armature between 90* and270* from the coil slot from which it emanates in being brought intojuxtaposition to the selected commutator hook.
 3. The method of claim 1,wherein during the first movement of the lead circumferentially aboutthe axis of the armature, the lead is placed adjacent to one side of theselected hook, and wherein during the second movement of the lead(circumferentially about the axis of the armature) , the lead is carriedunder and placed at the opposite side of the selected hook(.) , saidselected hook being unshielded only during the time the lead is carriedunder said hook.
 4. The method of claim 1, wherein a pair of coils aresimultaneously wound in two pairs of coil slots, and wherein the endingleads from the two coils are simultaneously engaged with selectedcommutator hooks, while all of the other hooks remain shielded.